The Analytical Laboratory performs routine analyses for monitoring purposes on water from a range of sources, including wastewater treatment plants (WWTP), industries, landfill, catchments, dams and composting plants.
Our clients include City of Cape Town departments such as Wastewater, Water Demand Management and Solid Waste as well as other internal and external clients.
Wastewater
Samples from 26 Wastewater Treatment Plants in Cape Town are taken by the Wastewater Treatment Plant (WWTP) staff and submitted to the Laboratory for testing. Samples are analysed on a weekly basis for chemical and physical determinants. Heavy metals and fluorides are determined once a month. CN and Phenol levels are determined as well.
The weekly chemical determinants include:
- pH, and Conductivity
- Chemical Oxygen Demand
- Ammonia
- Nitrate/Nitrite
- Total Kejldahl Nitrogen
- Total Phosphorous
- Ortho Phosphate
- Chloride
- lkalinity
Our weekly physical analysis includes:
- Settleable solids
- Total suspended and volatile solids
- Solids on sludges
We also check the following heavy metals:
- Aluminium
- Arsenic
- Cadmium
- Cobalt
- Chromium
- Copper
- Iron
- Manganese
- Molybdinum
- Nickel
- Lead
- Selenium
- Serium
- Vanadium
- Zinc
- Calcium
- Magnesium
- Sodium
- Potassium
- Boron
- Sulphate
- Mercury
Samples are taken at various stages of the biological treatment process, starting with the raw influent wastewater and ending with the final effluent that is discharged into the river. The results are reported to the Wastewater Department on a weekly basis and are used in the operations of the WWTPs.
Monitoring of WWTPs' performance is important as it gives us an indication of the effluent quality that is discharged into our environment and an indication as to what extent the environment is being polluted. The Department of Water Affairs has general standards for wastewater final effluent and the percentage of compliance for each WWTP is assessed by DWA every 18 months as part of their Green Drop Certification audit.
Analyses are performed by qualified technicians and support staff that ensure that ISO 17025 requirements are met. Sophisticated equipment is employed in order to minimise errors and to improve on the testing turn-around time.
Industries
More than 300 industries throughout the Cape metropole as are regularly sampled. Each industry is sampled four times in a six month cycle as per the Wastewater By-Law using our internal samplers. Monitoring industries is essential to prevent harmful substances entering the sewer system and negatively affecting the operation of the WWTW.
All the sampling points are evaluated by Water Pollution Control Inspectors who then issue penalties for samples that are non-compliant according to the By-Law.
On site tests performed are pH and Temperature.
The routine chemical determinants include:
Other routine determinants which are industry specific are:
- Cyanide
- Chloride
- Cadmium
- Chromium
- Copper
- Iron
- Zinc
- Lead
Landfill sites
There are six landfill sites in the Cape metropole which are also regularly monitored. Three of these are active. Boreholes in the vicinity of the sites are sampled to monitor groundwater and leachates samples are taken to determine pollution levels. Monitoring of a landfill site continues even if the site is closed for dumping.
The determinants include:
- pH, and Conductivity
- Chemical Oxygen Demand
- Ammonia
- Nitrate/Nitrite
- Ortho Phosphate
- Chloride
- Alkalinity
- Fluoride
- Cyanide
- Phenol
- Total Suspended Solids
- BOD
- Potassium
- Sulphate
- Sodium
- Copper
- Calsium
- Manganese
- Magnesium
- Chromium
- Cadmium
- Lead
- Mercury
- Arsenic
- Boron
Catchments
More than 100 river, canal and vlei (shallow lakes) points are monitored across the Cape metropole. Samplers do monthly routine visits to all these points, recording temperatures and dissolved oxygen on site, and collecting chemical and bacteriological samples. The Analytical Laboratory performs the chemical analysis on these samples and reports it to the Bacteriological Section, which then reports to their clients.
The routine determinants analysed by the Analytical Laboratory include: 
- pH, and Conductivity
- Chemical Oxygen Demand
- Ammonia
- Nitrate/Nitrite
- Total Phosphorous
- Ortho Phosphate
- Total Persulphate Oxidisable Nitrogen
- Total Suspended Solids
Instrumentation
Analyses are performed by qualified technicians and support staff that ensure that ISO 17025 requirements are met. Sophisticated equipment is employed in order to minimise errors and also to improve on testing turn-around time.
Instruments include: